Question

A 2000 kg car pushes a 3000 kg truck that has a dead battery. The ground pushes forward on the car with a force of 6000 N. What is the magnitude of the force that the truck exerts on the car? Ignore any friction forces.


My work/attempts:

I've drawn a for body diagram for the two of them but am unsure how to solve for the Force sine I am not given an acceleration/velocity/etc.

Answer 1

well, I suppose they both have the same acceleration, call it a

The total mass is 5000 kg
The total force on the system is 6000 N
so
a = 6000/5000 = (6/5) m/s^2

Now how much of that is on the truck?
F = 3000 a = 3000 (6/5) = 3600 Newtons
from the car on the truck
so the force the truck exerts on the car is -3600 Newtons (third law, equal magnitude and opposite direction)